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Re: Normalizing calls in AviSoft

Subject: Re: Normalizing calls in AviSoft
From: "Raimund" animalsounds
Date: Mon Jan 11, 2010 12:49 am ((PST))
Hi Aliza,

as Steve already pointed out, depending on the structure of the sounds, 
normalizing the waveform does not mean that the peak magnitudes of the 
spectrogram will be aligned. Even calculating the root mean square would not 
help in this case. 

Though, it is possible to normalize the spectrogram display contrast to the 
maximum spectrogram magnitude by activating the "autogain" option on the 
spectrogram window command "Display"/"Display Parameters...". Note that this 
option does not change the waveform - it only adjusts the contrast of the 
spectrogram display.

If you need to measure certain sound parameters by using the Automatic 
Parameter Measurements tool, you could activate the "Element separation" option 
"relative to maximum". This will make sure that the element detection 
thresholds will be referenced to the peak magnitude of the entire spectrogram.

You might also contact me directly through support <at>


Avisoft Bioacoustics

--- In  "alizaleroux" <> wrote:
> I have a technical question which I suspect has a straightforward answer that 
> I have somehow just not grasped...
> Does anyone know of a way to batch process a number of vocalizations (some 
> very loud, some very soft) so that their maximum amplitudes are all the same, 
> using AviSoft software? 
> I have several 100 vocalizations that I want to analyze in AviSoft. As these 
> recordings were done under natural conditions -- I had varying distances 
> between the calling monkey and my microphone -- my spectrograms all have 
> different amplitudes.
> I want to normalize all these spectrograms to have identical maximum 
> amplitudes. There is a "normalize" function under the Edit/Volume menu but I 
> can't seem to find the way to get all the different spectrograms to have the 
> same amplitude maxima. If I specify a certain % in the Normalize tab the 
> different calls still turn out to have very different maximum amplitudes.
> I can adjust the individual spectrograms' amplitudes to a specific value by 
> multiplying/ dividing it with a different value for each spectrogram but this 
> forces me to determine that value for each call individually, and apply the 
> math to each spectrogram individually. I'm certain there has to be an easier 
> way.
> Thanks so much for your help!
> Aliza

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